Scarifier



H. C; LA RUE s'cARIFiER Filed June 11, 1940 Jun cf 1,1943.

3 Sheefs-Sheet 1 Jun 1, 1943.

H. C. LA RUE SCARIFIER Filed June 11, 1940 3 Sheets-Sheet 2 June 1, 1943.

" .S'CARIFIER I V 3 Sheets-Sheet 3 .H. c. ILA RUE 2,320,365

File d June ll, 1940 Patented June 1, 1943 SCARIFIER Herschel C. La ltue, Ashfork, Ariz., assignor of one-half to Edward S. Hubbell, Paulden, Ariz.

Application June 11, 1940, Serial No. 339,956

13 Claims.

The present invention relates to a scarifying apparatus adapted particularly for use in road or pavement construction and reconstruction work. In the past it has-been the practice to form scariflers with a frame construction having a plurality of scarifying teeth at the rear of the frame, and road engaging wheels mounted in front of and adjacent to the scarifying teeth. The device is usually adapted to ,be supported at its forward end upon a traction-unit or other power means. Furthermore, the road engaging wheels are so mounted as to swing downwardly and rearwardly into cose proximity with the scarifying teeth, when it is desired to raise the teeth to inoperative position.

I have ascertained from actual practice and experience that there are certain disadvantages in constructions of this type. For instance, I have found that when it is desired to raise the scarifying teeth out of the ground into inoperative position, the downward and rearward movement of the road wheels will, in many instances, jam or wedge any loose material against the scarifying teeth. In other words, and particularly when digging in hard surfaces, rocks or othe hard material will be jammed or wedged between the wheels and teeth, and this wedging action becomes greater as the wheels continue 'theirdownward and rearward movement. It

will be apparent that this is an objectionable feature which not only interferes with the operation of the device, but in some cases, causes injury to the apparatus.

' The present invention is designed to eliminate this objectionable feature by providing a scarifler construction in which the road wheels are so mounted as to swing downwardly and forwardly away from the scarifyin'g teeth when the device is operated to raise the scarifying teeth to inoperative position. With this construction, there s no possibility of jamming material o of injury to the device; since the road wheels move further away from the scarifying teeth as they swing downwardly into ground engaging position.

An ther object of the invention is to operate .the wheel forks upon which the road wheels are mountedso that a rearward pull is exerted on the whee forks above the pivot point of the forks when the road wheels are to be moved downwardly and forwardly to raise the scarifying teeth to inoperative position. This rearward pull is effected from the extreme rear of the frame of the scar'fler and efi'ects a lifting action on the rear end of the scarifier, as the teeth are being raised to inoperative position. With the prior type of scarifler, the pull is usually from the front end of the ripper which not only fails to aid in raising the rear end, but also causes a strain through the center of the scarifler.

A further feature of the invention is to provide spring means associated with the road wheels and wheel forks to constantly urge the wheels to inoperative position. This is an asset when working in hard material where it is desired to provide as much weight as possible to assist-the teeth in digging into the material. With the present construction. the operator may actuate the apparatus so that the road wheels will be raised up into the frame out of engagement with the surface of the ground that is being worked, thereby utilizing the entire weight of the wheels in the scarifying operation.

With the foregoing and other objects in view, the invention will now be more fully described, reference being had to the accompanying drawings, in which:

Figure l is a top plan view of the scarifier;

Figure 2 is a side elevation thereof;

Figure 3 is a section taken on line 3-3 of Figure 2:

Figure 4 is a plan view of a modified form. of the scarifier, and

Figure 5 is a side elevation thereof.

Referring now to the drawings, the numeral l0 designates generally my scarifier or ripper, which consists of a main frame H. The main requisite of the frame i that it be rigid and sturdy, and while it may take different forms, I prefer that it be constructed in the manner shown in the drawings. Referring particularly to Figure 1. it will be observed that the frame comprises a pair of central longitudinal frame member 12 and I3, respectively, and outside longitudinal members It and i5. All of these longitudinal frame members are connected by transverse cross frame members l6 and IT. The central frame members l2 and I3 extend forwardly of the outer members It and I5 and are connected at their extreme forward ends by a cross bar Hi. In addition to the longitudinal frame memhers, I also provide a pair of frame elements l9 and 20, each of which is positioned between one of the inner and outer longitudinal frame membars. The rear ends of the elements I9 and 20 are secured to the cross frame member I! and at a point intermediate its ends each element is bent so as to converge inwardly and forwardly to cooperate with its complementary member to form a substantially triangular shaped forward frame portion 2|. At the extreme forward end nected by cross pieces 22 which constitute means for supporting a coupling element 23.

The central frame members l2 and I3 extend forwardly of the outer members l4 and I5 to a point where they contact and are secured to the converging forward portions of the elements l3 and 2|]. The cross bar I8 is also connected to these forwardly converging elements (see Figure 1). All of these frame members and elements may be secured together in any desired manner, such as by riveting or welding to provide the rigid sturdy scarifier frame A plurality of scarifying teeth 24 are rigidly secured to the rear end of the frame The scarifying teeth may consist of any desired number and may be secured to the frame in any desired manner, so long as they form with the frame a rigid solid structure which is capable of withstanding the usual scarifying or ripping operations.

On each side of the main frame at a point intermediate the scarifying teeth and the front of the frame are mounted a pair of wheel forks 25. These forks are mounted each on a stub shaft or pivot pin 26 journaled between its respective outer longitudinal frame member and one of the intermediate members I9 or 20. For

instance, the left hand stub shaft 26 (see Figure 1) is journaled between the frame members 4 and I9, while the right hand stub shaft is journaled between the members l5 and 20. Each wheel fork is formed of a pair of identical, spaced plates 21 and 28 which are fixed to their respective stub shaft 26. Each plate is constructed substantially in the form of a right angle triangle having a base 29 and sides 38 and 3|, respectively, the apex of each plate being normally elevated a substantial distance above the top of the frame II, and fixed to a tubular cross bar or yoke 32.

As shown in Figure 1, this yoke extends across the entire width of the frame and connects the wheel forks toform a rigid structure whereby they will move or swing as a unit about their pivots.

On each wheel fork is journaled a road wheel 33 and the shaft 34 upon which the wheel is mounted is fixed to the extreme rear of the plates, that is, where the sides 29 and 3| meet. The shaft 34 upon which the wheel 33 is journaled constitutes one of the elements for rigidly securing the plates 21 and 28 in spaced relation. Referring to Figure 2 the wheels are shown in one of their operative positions, and it will be observed that thespacing between the teeth 24, wheels 33 and pivot point 26 is such as to permit the wheel forks to swing the wheels forwardly and downwardly when it is desired to raise the teeth 24 to inoperative position. Furthermore, the spacing between the wheels and the teeth is such that no jamming of loosened material will occur, and it will be apparent that even if any material is originally wedged between the wheels and the teeth, this material will be immediately freed, since the downward and forward swinging of the wheels will move the wheels away from the teeth.

The means for actuating the road wheels and wheel forks comprises a cable and pulley construction consisting of a main drum 34 and auxiliary drums 35 and 36 which are concentric with and project outwardly from opposite sides of the drum 34. As clearly shown in Figure 3, all of these drums are mounted on a common shaft 31 journaled between a pair of blocks 38. Each block is supported upon and secured to a plate 38 of the frame 2|, the elements I9 and 20 are conforming a front platform or flooring supported upon the forwardly converging frame elements 2|. This plate is provided with a central opening to permit the drum 34 to project downwardly somewhat into the frame structure.

Referringto Figures 1 and 2, it will be observed that the drums are mounted forwardly of the pivot point 26 of the wheel forks 26. A pair of pulleys 40 and 4| are mounted at the extreme rear end of the frame in alignment with the small drums, that is, the pulley 40 is in alignment with the drum 35 while the pulley 4| is aligned with the drum 36. A pair of cables 42 and 43 operatively connect the small drums with the cross yoke 32. The forward end of each of these cables is wound upon its respective drum and then passes rearwardly around one of the pulleys and then upwardly where its other end is secured to the cross yoke. A power take-off cable 44 is wound upon the large drum 34. The other end of cable 44 is adapted to be operatively connected to any desired power take-oif (not shown), preferably mounted upon a traction device (also not shown) which is adapted to be coupled to the scarifler and pull the same during the scarifying operation.

Assuming that the apparatus is in the position shown in Figure 2 and that it is desired to raise the scarifying teeth 24 to inoperative position, the operator then actuates the power take-off to unwind the cable 44 from the drum 34. This operation causes the cables 42 and 43 to be wound upon the small drums 35 and 36, respectively, which action moves these cables about their pulleys 40 and 4|, exerting a downward and rearward pull upon the top portions of the wheel forks, that is, upon the cross yoke 32. As the cables 42 and 43 are being wound upon their drums the wheel forks are gradually moved about pivots 26, thus swinging the road wheels 33 forwardly and downwardly away from the teeth 24. At the same time this action will gradually raise the scarifying teeth out of contact with the ground to their inoperative positions where the scarifier may then be moved to any other desired position for further work. 7

While theconstruction as thus far described is quite efllcient, I have found from actual experience that where the scarifler is to be used in work upon a hard or rocky surface, it is desirable to apply more pressure or weight to the teeth than is necessary when a reasonably soft surface is to be acted upon. For this reason the present construction is designed to effectively scarify a sur face, regardless of whether it, is relatively soft or hard and rocky. This is accomplished. by providing means for raising the road wheels 33 up into the frame II to a point where they will not constitute traction wheels nor limit the depth to which the teeth can penetrate, such as shown in Figure 2. On each side of the center of the frame II and between the central longitudinal framemembers I2 and I3 are mounted a pair of tubular casings 45 and 45. Each casing extends longitudinally of its respective'frame member |2 or and has its rear end supported by and connected to the cross frame member H. The front of each casing is connected to the cross element 8. This element is provided with a pair of holes or openings 46, one for each casing, which are located at the center of their respective casings. Each casing encloses and supports a coil spring 41 which in its position of rest, that is, when it is not under compression, occupies the whole length of its casing.

'asaaacc As shown in Figure 1, each coil spring and casing is associated with a cable 4'8 which passes through the opening 46 and extends entirely through the coil spring. This end of the cable is dead-ended or fixed to a metal plate or disc 89 which abuts the rear end of the coil spring and is adapted when force is applied to the cable to compress the coil spring.

In advance of each casing a front pulley 56 is mounted upon an angle bracket 51 which is secured to the front cross element IS. The lower run of the pulley is in line with the hole or opening 43 so that it will properly receive the cable 88. This cable, after passing around the pulley B0, is

then extended upwardly and rearwardly where its other end is fixed or dead-ended on the tubular v upper portions of the wheel forks are moved rearwardly to lower the whe'e1s33, a rearward pull will be applied to the cablesfflfi, which, in turn, wfll move the plates 39 forwardly and thus compress the coil springs 41.

When it is desired to lower the scarifler teeth to operative position, it is merely necessary to release the power take-off cable 45. Since the springs, in the lowered positions of the wheels 33, are under compression, release of the cable 53 will permit the springs to expand, exerting a pull on each of the cables 48 which, in turn, will effect an upward pull on the wheel forks and wheels. When working in a rocky or hard surface, the best results will be obtained by raising the wheels 33 a greater distance than that shown in Figure l of the drawings. This is easily and quickly accomplished by further releasing the power takeoff cable 43 to permit further expansion of the coil springs. This will have the effect of raising the wheels 33 to a point where their lower extremities are substantially contained within the scarifler frame. In other words, the wheels are raised to such a height that they will not contact or engage the surface which is being scarifled or worked upon. Thus, not only the whole weight -are raised to their fullest extent than when the wheels are in the position shown in Figure 1. It will be apparent, therefore, that the present invention is not only adaptable to relatively soft ground where the pressure upon the scarifler teeth need not be excessive, but that the mechanism is also effective when it is desired to soarify a rocky or hard surface. In the prior constructions, wherein the road wheels are mounted to swing downwardly and rearwardly, I have also found that when it is desired to lower the scarifying teeth to operative position, it is usually necessary to back up on the tractor or other power means before the teeth can be lowered. This undesirable feature is eliminated in the present invention, in that the teeth may be quickly lowered by merely releasing the power take-off cable 44 and permitting the coil springs to raise the road wheels andlower the scarifying teeth.

While the relative sizesof the largeand small drums may be varied as desired, I prefer to have the size of these drums in a ratio of three to one, that is, the diameter of the large drum 34 is three times that of the diameter of the small drums 35 and 36. This gives a three to one ratio between the pull on the cables 42 and 63 and the power take-off cable 44. In other words, a three foot take-up of the cable 44 will move the yoke 32 rearwardly one foot, providing a three to one reduction; In order to provide a further reduction in movement between the power take-oil and the road wheels, the length of the base 29 of each plate forming the wheel forks is formed substantiallyone-half the length of the other sides of the plates, thus giving a two to one ratio. Thus the total .ratio between the effective pull on the power take-off cable 44 and the movement a take-up of the cable M will swingthe road wheels wheels one foot about their pivots, effecting a five to one reduction; This may, of course, be varied as desired, but I have found that this is quite effective in the raising and lowering of the 33. If desired, any type oflatching or locking means may be'applied either to the drum 34 or to the power take-01f (not shown) for the purpose of maintaining the scarifying teeth and the road wheels in any desired position of adjustment. With such a locking means,

it would not be necessary to apply constant pressure to the cable 44 against the tension of the springs 41.

Referring now to Figures 4 and 5, there is disclosed a modified form of the invention in which the several drums and the spring mecha nism are eliminated. In this construction the frame Si is rigid and sturdy, similarto frame I I. and is provided with a relatively wide rear section 52 upon which scarifler teeth "53 are secured. It is to be understood that these teeth, similar to the teeth 24 are detachably mounted in the frame so that they may be replaced as it becomes necessary. The frame is provided with an intermediate section 54 of less width than the section 52 so as to accommodate road wheels 55 in advance of the scarifler teeth. Each wheel is mounted upon a wheel fork 56 similar in construction to the wheel forks 25, that is, each fork comprises a pair of identical spaced plates 51 between which the road wheel is suitably journalled. A transverse shaft 58 is journalled in the intermediate frame section 54 with its ends pro- ,iecting from opposite sides of this sect on and upon which the wheel forks are secured, It is to be understood, however, that if desired. a pair of stub axles may be provided similar. to those illustrated in Figures 1 to 3.

A cross bar or yoke 59 connects the upper portions of the wheel forks so as to -provide a rigid construction which will permit the wheel forks and road wheels to be rotated about the axis 58 as a unit. Abracket 80 is pivoted cenfrally of the yoke 59 and is provided with a downwardly extending portion upon which a pulley 6| is journalled. A second bracket 62 is mounted upon the frame section 52 in alignment with the bracket 50. Upon the bracket 62 are coaxially journalled a pair of pulleys 53 and 64. Referring to Figure 4, it will be observed that a sin le rope or cable 65 is utilized in operating the wheel forks and road wheels. One end 66 of this cable is dead-ended or secured to the bracket 50 and extends downwardly and rearwardly and around pulley 54. The cable then extends upwardly to the bracket 60, around pulley BI and then downwardly to and around pulley 4 63. The cable finally extends forwardly from pulley 63 throughout the length of the sacrifler, where its other end is secured to a power takeoff (not shown) which may be mounted on a tractor or other power unit (also not shown) to which the scarifier is adapted to be coupled by means of the coupling mechanism 61.

It will be apparent that this modified form of the invention embodies the same basic principles as the embodiment shown in Figures 1 to 3; that is, operation of the device to raise the scarifier teeth 53 to inoperative position above the ground, swings the road wheels 55 forwardly and downwardly away from the teeth 53. Assuming, therefore, that the teeth 53 are in the position shown in Figure 5 and that it is desired to raise the teeth to inoperative position, it is merely necessary to exert a forward pull upon the cable 65. This will have the effect of moving the pulley 6| rearwardly and downwardly toward the pulley 63. This movement will also swing the cross bar or yoke 59 and the upper portions of the wheel forks 56 rearwardly and downwardly about the pivot 58. Movement will thus be imparted to the road wheels 55 whereby these wheels are moved away from the teeth 53 so that the teeth and the rear section 52 of the frame are'raised to inoperative position, where the scarifier may be ,moved to another location.

In this form of the invention, as well as in the construction shown in Figures 1 to 3, it will be observed that the arrangement is such that when the wheel forks are operated to raise the teeth and the rear end of the frame, a rearward pull is exerted on the wheel forks above the pivot point of the forks. The rearward pull is effected from the extreme rear of the frame of the scarifier and effects a lifting action on the rear end of the scarifier as the teeth are being raised to inoperative position. With prior types of scarifiers this pull is usually from the front end of the ripper which not only fails to aid in raising the rear end but also causes a strain through the center of the scarifier. It'will be apparent that the, present construction greatly facilitatesthe lifting or raising operation of the scarifier teeth and the rear end of the frame. V

It is to be understood that the invention is not limited to details of construction shown in the drawings and described in the specification, and that the phraseology employed in the specification is for the purpose of description and not of limitation.

I claim:

1. A scarifier comprising a rigid frame adapted to be attached at its forward end to a traction unit, a plurality of scarifying teeth secured at the rear of said frame, a wheel fork pivotally mounted on the frame at a point between the mounting of the scarifying teeth and the forward end of the frame, a road wheel mounted on the wheel fork and located in rear of the pivot point of said fork when the wheel is in raised position, and means for actuating said wheel fork to raise and lower the wheel and to raise and lower the scarifying teeth, said operating means including wardly and forwardly away from the scarifying teeth and raise said teeth to inoperative position.

2. A scarifier comprising a rigid frame adapted to be attached at its forward end to a traction unit, a plurality of scarifying teeth secured at the rear of said frame, a wheel fork pivotally mounted on the frame at a point between the mounting of the scarifying teeth and the forward end of the frame, a. road wheel mounted on the wheel fork and located in rear of the pivot point of said fork when the wheel is in raised position, and means for actuating said wheel fork to raise and lower the wheel and to raise and lower the scarifying teeth, said operating means including a pulley mounted at the rear of the frame, and a cable passing around the pulley and having one end connected to the wheel fork above the pivot point of said fork, the other end of said cable extending forwardly of the pulleywhereby power applied thereto will exert a rearward pull on said wheel fork to swing the road wheel downwardly and forwardly away from the scarifying teeth and raise said teeth to inoperative position, said operating means also including spring mechanism mounted on the frame, and a cable having one end connectedto the wheel fork above the pivot point of said fork, the other end of said cable being connected to said spring a pulley mounted at the rear of the frame, and

a cable passing around the pulley and having one end connected to the wheel fork above the pivot point of said fork, the other end of said cable extending forwardly of .the'pulley whereby power applied thereto will exert a rearward pull on said wheel fork to swing the road wheel downmechanism and tending to compress the latter as the wheel fork is moved aboutits pivot to swing the road wheel forwardly and downwardly.

. 3. A scarifier comprising a rigid frame adapted to be attached at its forward end to a traction unit, a plurality of scarifying teeth secured at the rear of said frame, a wheel fork pivotally mounted on the frame at a point between the mounting of the scarifying teeth and the forward end of the frame, a road wheel mounted on the wheel fork and located in rear of the pivot point of said fork when the wheel is in raised position.

and means for actuating said wheel fork to raise and lower the wheel and to raise and lower the scarifying teeth, said operating means including a pulley mounted at the rear of the frame, and a cable passing around the pulley and having one end connected to the wheel fork above the pivot point of said fork, the other end of said .cable extending forwardly of the pulley whereby power applied thereto will exert a rearward pull on said wheel fork to swing the road wheel downwardly and forwardly away from the scarifying teeth and raise said teeth to inoperative position, said operating means also including a coil spring mounted on the frame, a pulley mounted on the frame in advance of the coil spring, and a cable passing around the pulley and having one end connecte dto the coil spring and its other end connected to the wheel fork above its pivot point, whereby pull on the first mentioned cable to swing the road wheel forwardly and downwardly will compress the coil spring.

4. A s'carifier comprising a rigid frame adapted to be attached at its forward end to a traction unit, a plurality of scarifying teeth secured at the rear of said frame, a wheel fork pivotally mounted on the frame at a point between the mounting of the scarifying teeth and the forward end of the frame, a road wheel mounted on the wheel fork and, located in rear of the pivot point of said fork when the wheel is in raised position, and means for actuating said wheel fork to raise and lower the wheel and to raise and lower the scarifying teeth, said operating means including a pulley mounted at the rear of the frame. a cable drum mounted on the frame in advance of the pivot point of the wheel fork, a cable passing around the pulley and having one end connected to the wheel fork adjacent its top.

the other. end of the cable being wound on said drum, a coil spring mounted longitudinally of the frame, a second pulley mounted on the frame in advance of the coil spring, and a second cable passing around the second pulley and having one end passing through and connected to the rear end of the coil spring and its other end connected to the wheel fork adjacent its upper end, whereby rotation of the drum to wind the first cable will move the wheel fork about its pivot against the tension of the coil spring and swing the road wheel forwardly and downwardly away from the scarifying teeth and raise said teeth to inoperative position.

5. A scariiier comprising a rigid frame adapted to be attached at its forward end to a traction unit, a plurality of scarifyin'g teeth secured at the rear of said frame, a wheel fork pivotally mounted on the frame at a point between the mounting of the scarifying teeth and the forward end of the frame, a road wheel mounted on the wheel fork and located in rear of the pivot point of said fork when the wheel is in raised position, and means for actuating said wheel fork to raise and lower the wheel and to raise and lower the scarifying teeth; said operating means including mechanism for exerting a rearward pull on said wheel fork above the pivot point of said fork to swing the road wheel down wardly and forwardly away from the scarifying teeth and raise said teeth to inoperative position, said operating means also including a coil spring casing mounted longitudinally of the frame, and having its longitudinal center at substantially the pivot point of the wheel fork, a coil spring positioned within said casing, a pulley mounted on the frame in advance of the casing and spring, and a cable passing over the pulley and having one end passing through the front of the casing and secured to the rear end of the coil spring, the other end of the cable being connected to the wheel fork above its pivot point whereby a rearward pull on said wheel fork will compress the coil spring and thereby lower the road wheel against the tension of the spring.

6. A scarifier comprising a rigid frame adapted to be attached at its forward end to a traction unit, a plurality of scarifying teeth secured at the rear of said frame, -a pair of wheel forks, one pivotally mounted on each side of the frame at a point between the mounting of the scarifying teeth and the forward end of the frame, road wheels, each mounted on a wheel fork and located in rear of the pivot point of said fork when the wheel is in raised position, a cross yoke rigidly connecting the top portions of the wheel forks to permit the road wheels to be actuated together, a pair of pulleys mounted in spaced relation at the rear of the framewand inwardly of the ends of the cross yoke, a cent'ral power take-off drum mountedon the frame in advance of the pivot points of the wheel forks, a pair of drums concentrically mounted upon opposite sides and of smaller diameter than the central drum, a pair of cables passing around the pulleys and each having one end connected to the cross yoke, the other end of each cable being wound upon one of the small drums, and a power take-off cable having one when power is applied thereto to rotate said drums and wind the first mentioned cables on the smaller drums to thereby exerta rearward pull on the cross yoke and swing the road wheels forwardly and downwardly away from the scarifying teeth.

7. A scarifier comprising a rigid frame adapted to be attached at its forward end to a traction unit, a plurality of scarifying teeth secured at the rear of said frame, a pair of wheel forks, one pivotally mounted on each side of the frame at a point between the mounting of the scarifying teeth and the forward end of the frame,

road wheels, each mounted on a wheel fork and located in rear of the pivot point of said fork when the wheel is in raised position, a cross, yoke rigidly connecting-the top portions of the wheel forks to permit the road wheels to be actuated together, a pair of pulleys mounted in spaced relation at the rear of the frame and inwardly of the ends of the cross yoke, a central power take-off drum mounted on the frame in advance of the pivot points of the wheel forks,

a pair of drums concentrically mounted upon opposite sides and of smaller diameter than the central drum, a pair of cables passing around the pulleys and each having one end connected to the cross yoke, the other end of each cable being wound upon one of the small drums, a power take-off cable having one end wound on the central drum and adapted when power is applied thereto to rotate said drums and wind the first mentioned cables on the small drums to thereby exert a rearward pull on the cross yoke and swing the road wheels forwardly and downwardly away from the scarifying teeth, and a pair of springs mounted upon opposite sides of the frame and operatively connected to the cross yoke to oppose the rearward pull thereon and the lowering of the road wheels.

8. A scarifier comprising a rigid frame adapted to be attached at its forward end to a traction unit, a plurality of scarifying teeth secured at the rear of said frame, a pair of wheel forks, one pivotally mounted on each side of the frame at a point between the mounting of the-scarifying teeth and the forward end of the frame, road wheels, each mounted on a wheel fork and located in rear of the pivot point of said fork when the wheel is in raised position, a cross yoke rigidly connecting the top portions of the wheel forks to permit the road wheels to be actuated of cables passing around the pulleys and each having one end connected to the cross yoke, the other end of each cable being wound upon one of the small drums, a power take-off cable having one end wound on the central drum and adapted when power is applied thereto to rotate said drums and windthe first mentioned cables on the small drums to thereby exert a rearward pull on the cross yoke and swing the road wheels forwardly and downwardly away from the scarifying teeth, a pair of coil springs mounted longitudinally of and upon opposite sides of the frame,

a second pair of pulleys mounted on the frame end wound on the central drum and adapted in" advance of the coil springs, and a second pair of cables, each passing around a pulley and having one end secured to the rear end of a coil spring, the other end of each cable being connected to the cross yoke whereby the rearward pull thereon will cause compression of the springs to oppose the downward and forward swing of the road wheels.

' 9. A scarifler comprising a rigid frame adapted to be attached at its forward end to a traction unit, a plurality of scarifying teeth secured at the rear of said frame, a wheel fork pivotally mounted on the frame at a point between the mounting of the scarifying teeth and the forward end of the frame, a road wheel mounted on the wheel fork and located in rear of the pivot point of said fork when the wheel is in raised position, and means for actuating said wheel fork to raise and lower the wheel and to raise and lower the scarifying teeth, said operating means including a pair of pulleys mounted at the rear of the frame, a pulley movable with the wheel fork above the pivot point of the fork, and a cable passing around the pulleys and having one end connected to the wheel fork above its pivot point, the other-end of said cable extending forwardly of the rearwardly mounted pulleys whereby power applied thereto will exert a rearward pull on said wheel fork to swing the road wheel downwardly and forwardly away from the scarifying teeth and raise said teeth to inoperative position.

10. A scarifler comprising a rigid frame adapted to be attached at its forward end to a traction unit, a plurality of scarifying teeth secured at the rear of said frame, a pair of wheel forks, one pivotally mounted on each side of the frame at a point between the mounting of the scarifying teeth and the forward end of the frame, road wheels, each mounted on a wheel fork and located in rear of the pivot point of said fork when the wheel is in raised position, a cross yoke rigidly connecting the top portions of the wheel forks to permit the road wheels to be actuated together, a pair of pulleys mounted at the rear of the frame, a pulley carried by the cross yoke, and a cable passing around the pulleys and having one end secured to the cross yoke, the other end of said cable extending forwardly of the rearwardly mounted pulleys whereby power applied thereto will exert a rearward pull on said wheel forks to swing the road wheels downwardly and forwardly away from the scarifying teeth and raise said teeth to inoperative position.

11. A scarifier comprising a rigid frame adapted to be attached at its forward end to a traction unit, a plurality of scarifying teeth secured at the rear of said frame, a wheel fork pivotally mounted on the frame at a point between the mounting of the scarifying teeth and the forward end of the frame, a road wheel mounted on the wheel fork and located in rear of the pivot point of said fork when the wheel is in raised position, and means for actuating said wheel fork to raise and lower the wheel and to raise and lower the scarifying teeth, said operating means including a cable guide mounted adjacent the rear of the frame, and a cable engaging said guide and having one end connected to the wheel fork above the pivot point of said fork, the other end of said cable extending forwardly of the guide whereby power applied to the cable will exert a rearward pull on said wheel fork to swing the road wheel downwardly and forwardly away from the scarifying teeth and raise said teeth to inoperative position.

12. A scarifler comprising a rigid frame adapted to be attached at its forward end to atraction unit, a plurality of scarifying teeth mounted adjacent the rear of the frame, a wheel fork pivotally mounted on the frame at a point between the mounting of the scarifying teeth and the forward end of the frame, a road wheel pivotally mounted on the wheel fork, the pivot point of said wheel fork being forward of the wheel hearing when the wheel is in raised position, and means for actuating said wheel fork to raise and lower the wheel and the scarifying teeth, said operating means including a cable guide supported on the frame in rear of the wheel fork pivot, and a cable operatively engaging said guide and also the wheel fork above the pivot point of said fork, one end of said cable extending forwardly of the guide whereby power applied to the cable will exert a rearward pull on said wheel fork to swing the road wheel downwardly and forwardly away from the scarifying teeth and raise said teeth to inoperative position.

13. A scarifier comprising a rigid frame adapted to be attached at its forward end to a traction unit, a, plurality of scarifying teeth mounted adjacent the rear of the frame, a pair of wheel forks, one pivotally mounted on each side of the frame at a point between the mounting of the scarifying teeth and the forward end of the frame, road wheels, each mounted on a wheel fork and located in rear of the pivot point ofsaid fork when the wheel is in raised position, a. cross yoke rigidly connecting the wheel forks to permit the road wheels to be actuated together, and means for actuating said wheel forks to raise and lower the wheels and the scarifying teeth, said operating means including a cable guide supported on the frame in rear of the wheel fork pivots, and a cable operatively engaging said guide and also'the cross yoke, one end of said cable extending forwardly of the guide whereby power applied to the cable will exert a rearward pull on said cross yoke and wheel forks to swing the road wheels downwardly and forwardly away from the scarifying teeth and raise said teeth to inoperative position.

HERSCHEL C. LA RUE. 

